Maybe someone is trolling but, taking action by splattering a customers car/house because it gets on your mower is a total load of bs. If I did that to a client or someone did it to me, I'd/you'd be cleaning it up or kicking your butt off my lawn. It's not like there isn't 20 guys right behind us willing to do our job for us.
We offer a service, so charge for the service provided. If the service is picking up poop and toys, charge for it.